*** The MAINT parameter specifies how access
paths are maintained for closed files.

While a file is open, the system maintains the access paths as
changes are made to the data (this data may be key field data of other file) in
the file.

But the same data can have access path in multiple file. Some files
may be open at that time and some file may be closed at that time. For open
file, the access path for will change at the time related data is modified. But
for closed file how the access path will change is being decided by this MAINT
parameter.

e.g. The account no. field may be used by many a files as a part of
composite key field. In such a case if a file is updating this account no.
field or adding one more account no.,in
such a case what should be the effect of this change if the other file using
this filed is not open at that time the change is made.

The three ways of maintaining access paths of closed files are:

ü*IMMED: Immediate maintenance of an access path
means that the access path is maintained as changes are made to its associated
data, regardless if the file is open.

ü*REBLD: Rebuild maintenance of an access path
means that the access path is only maintained while the file is open, not when
the file is closed; the access path is rebuilt when the file is opened the next
time. When a file with rebuild maintenance is closed, the system stops
maintaining the access path. When the file is opened again, the access path is
totally rebuilt.

ü*DLY: Delayed maintenance of an access path
means that any maintenance for the access path is done after the file member is
opened the next time and while it remains open. However, the access path is not
rebuilt as it is with rebuild maintenance. Updates to the access path are
collected from the time the member is closed until it is opened again. When it
is opened, only the collected changes are merged into the access path.

*Note: If you
do not specify the type of maintenance for a file, the default is immediate maintenance.